Friction catch



Dec. 12, 1961 c. E. HAFSTAD FRICTION CATCH Filed April 25, 1960INVENTOR. CARL E. HAF'STAD 5 T TOEN E YS United States Pat -n 3,012,803I FRICTION CATCH Carl E. Hafstad, 828 21st Ave. S., Minneapolis, Minn.Filed Apr. 25, 1960, Ser. No. 24,468 3 Claims. (Cl. 292-76) Thisinvention relates generally to door latch mechanisms, and moreparticularly it relates to a new and useful friction catch of the typewhich will yield under the application of a unidirectional force, asdistinguished from the more positive type of locking catch.

More specifically, my invention relates to and is in the nature of animprovement upon the disclosure of my previous application entitled DoorLatch Mechanism, Serial No. 823,429, filed on June 29, 1959, now PatentNo. 2,957,719, dated October 25, 1960. Some specific advantages of thisinvention over the above-noted previous application reside in theprovision of a friction catch which permits smaller constructionsthereof, is more silent and positive in its action, and more economicalto produce. Therefore, an important object of this invention is theprovisionof a friction catch inwhich the last mentioned features thereofrender the same particularly adaptable for use on the doors ofrelatively small cabinets. "Another object of this invention is theprovision of afriction' catch which is highly resistant againstaccidental opening since the same exerts a greater force against thedoor during opening movements than during closing movements thereof.

Other objects of this invention reside in the provision of a frictioncatch which is extremely simple in construction, inexpensive to produce,durable and strong throughout continued use, and highly eflicient in thevindication of its purposes. a

' The above and still further objects of my invention will becomeapparent from the following detailed specification, appended claims andattached drawings.

Referring to the drawings wherein like reference characters indicatelike parts or elements throughout the several views: I

FIG. 1 is a fragmentary view in elevation of cooperating door and jambmembers having my novel friction catch attached thereto, with some partsshown in section;

FIG. 2 is a sectional view taken on the line 22 of FIG. 3 is a sectionalview taken on the line 3--3 of FIG. 1;

FIG. 4 is a view similar to FIG. 3 and showing the relative position ofthe parts thereof during initial opening movement of the door member;

FIG. 5 is a view similar to FIG. 4 and showing the relative position ofthe'parts thereof during final closing movement of the door member; and

FIG. 6 is a view in perspective of the friction catch only.

Referring with greater particularly to the drawings, a door member,represented generally by the reference letter A, is movably mountedin ajamb member, represented generally by the reference letter B. Aconventional keeper element 1 is rigidly secured to the inner face b ofthe jamb member near the outer edge thereof by means of the fasteners 2.This invention resides specifically in the provision of a frictioncatch, represented generally by the reference numeral 3, the completelatch mechanism being represented generally by the reference numeral 4.

The friction catch includes a mounting bracket which is secured to thedoor member A adjacent the free edge a thereof by means of the fasteners6 which are received within the apertures 7 defined in the base portionor mounted end 8 of the mounting bracket 5, the apertures 3,012,803Patented be n, 1961 7 being elongated so as to provide for theadjustment of the mounting bracket 5 with relation to the free edge 1 ofthe door member A. The free or projecting end portion 9 of the mountingbracket 5 is bifurcated so as to define spaced spring-carrying generallyco-planar tabs or car portions 19.

As shown, a pair of elongated coil springs, each being representedgenerally by the reference characters 11a and 11b respectively, aresecured at their respective ends 12, preferably by welding or soldering,to the tabs 10 of the mounting bracket 5. As will hereinafter bedescribed, the springs 11a and 11b are disposed in such relationshipwith the keeper element 1 that their individual functionalcharacteristics combine to produce the novel friction catch 3. As seenparticularly in FIG. 1, the mounting bracket 5 is formed so that each ofthe springs 11a and 11b after being connected thereto lies in spacedparallel relationship to the adjacent surface e of the door member A. Inthis position, the respective axes of the springs 11a and 11b are spacedin general parallelism to the edge d of the door member A and are alsodisposed in general axial parallelism with one another. The springs 11aand 111; are so positioned on the mounting bracket 5 relative to thekeeper element 1 and further arranged in general longitudinal engagementwith one another that the outer spring lla disposed closest to thekeeper element 1 is so engaged by the keeper element 1 during initialopening movement of the door member A with respect to the jamb member Bthat concerted lateral deflection is imparted to both of said springs11a and 11b in the same lateral direction during said movement, as seenparticularly in FIG. 4. It should be obvious that such deflection duringsaid initial opening movement is accomplished first by the engagementand subsequent movement of the outer spring 11a with the keeper element1, followed by generally longitudinal engagement of the outer spring 11awith the inner spring 11b so that both of the springs 11a and 11b aregene'rally simultaneously deflected by the initial opening movement ofthe door member A. Thus, it is seen that a substantial force is requiredto open the door member A since both of the springs 11a and 11b must bedeflected. However, the

to the keeper element 1 is such that their function during final closingmovement of the door member A is quite different from their functiondurin the above-described opening movement.

FIG. 5 illustrates the function and action of the catch 3 during finalclosing movements of the door member A. As shown, the disposition of thecoil springs 11a and 11b is such that lateral deflection in anotherdirection from the deflection upon opening movement of the door memberis imparted only to the inner spring 11a during final closing movementof the door member A with respect to the jamb member B. Thus, the forceneeded to close the door member A is approximately only one-half of theforce needed to open the door member A. This relative difference in theapplied forces necessary to open and close the door member A withrespect to the jamb member B will be seen to be of substantial utility.One illustration of the merit of the above-described friction catch 3 isthe use of my invention on a structure such as a cabinet, not shown,wherein substantial air pressure is built up in the enclosure by theclosing action of the door. When my novel catch 3 is employed in such asituation, the door member A may be closed with relative case but theopening thereof is characterized by the need for the application of asubstantially greater opening force. The fact that the force required toclose the door member A is substantially less than the force required toopen it is also advantageous in that the noise 3 produced by striking ofthe door member A against the outer edge c of the jamb member B isthereby reduced. It should also be noted that the action of the keeperelement 1 against the springs 11a and 11b produces inherently less noisyoperation than conventional door latch mechanisms.

This invention has been thoroughly tested and found to be completelysatisfactory for the accomplishment of the above objects; and while Ihave chosen a preferred embodiment thereof, I wish it to be specificallyunderstood that the sarne may be modified without departure from thescope and spirit of the appended claims.

What I claim is:

1. In a latch mechanism for latching a door member mounted for openingand closing movements relative to a cooperating jamb member, and inwhich one of said members is provided with a rigidly mounted keeperelement, the improvement of a friction catch, said improvementcomprising a pair of elongated coil springs carried by the other of saidmembers in spaced relation thereto with their respective end portionsfixedly disposed with respect to said other of said members, said coilsprings being disposed in general axial parallelism with one an other,said coil springs being positioned on said other of said members ingeneral longitudinal engagement with one another and further arrangedrelative to said keeper element so that one of said springs is soengaged by said keeper element during initial opening movement of saiddoor member with respect to said jamb member that concerted lateraldeflection is imparted to both of said coil springs in the same lateraldirection during said movement, the disposition of said coil springsbeing such that lateral deflection in another direction is imparted onlyto said one of said springs during final closing movement of said doormember with respect to said jamb member.

2. In a latch mechanism for latching a door member mounted for openingand closing movements relative to a cooperating jamb member, and inwhich said jamb' member is provided with a rigidly mounted keeperelement, the improvement of a friction catch, said improvementcomprising a mounting bracket carried by the door member adjacent thefree edge thereof, and a pair of elongated coil springs having theirrespective end portions fixedly secured to said mounting bracket so thateach of said springs lies in spaced parallel relationship to said freeedge of said door member, said coil springs being disposed in generalaxial parallelism with one another and in general longitudinalengagement with one another and further arranged relative to said keeperelement so that one of said springs is so engaged by said keeper elementduring initial opening movement of said door member with respect to saidjamb member that concerted lateral deflection is imparted to both ofsaid coil springs in the same lateral direction during said movement,the disposition of said coil springs being such that lateral deflectionin another direction is imparted only to said one of said springs duringfinal closing movement of said door member with respect to said jambmember.

3. In a latch mechanism for latching a door member mounted for openingand closing movements relative to a cooperating jamb member, and inwhich said jamb member is provided with a rigidly mounted keeperelement, the improvement of a friction catch, said improvementcomprising a mounting bracket carried by the door member adjacent thefree edge thereof, said mounting bracket having a base portion adaptedfor sccurement to said door member and also having a laterallyprojecting end portion defined opposite of said base portion thereof,said end portion of said mounting bracket being bifurcated so as todefine spaced spring-carrying tabs, said improvement further comprisinga pair of elongated coil springs having their respective opposite endportions fixedly secured to said tabs of said mounting bracket so thateach of said springs lies in spaced parallel relationship to saidadjacent edge of said door member, said coil springs being disposed ingeneral axial parallelism with one another and in general longitudinalengagement with one another and further arranged relative to said keeperelement so that one of said springs is so engaged by said keeper elementduring initial opening movement of said door member with respect to saidjarnb member that concerted lateral deflection is imparted to both ofsaid coil springs in the same lateral direction during said movement,the disposition of said coil springs being such that lateral deflectionin another direction is imparted only to said one of said springs duringfinal closing movement of said door member with respect to said jambmember.

References Cited in the file of this patent UNITED STATES PATENTS2,559,145 Borchets July 3, 1951 FOREIGN PATENTS 487,749 Canada Nov. 4,1952

